The average temperature at 40,000 feet above sea level is -60 F.
56
The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
Your brain is 80% water.
525
Only 12,000 years ago there was a species closely related to modern humans called Homo floresiensis that had been living on an Indonesian Island. They used fire and rather advanced tools, yet were only about 3 feet tall and weighed around 25kg.
15
Each day, up to 150 species of life become extinct.
-23
It takes a photon 170,000 years to travel from the core of the Sun to the surface, but only 8 minutes to travel the rest of the way to Earth.
6
The only letter not appearing on the Periodic Table is the letter "J".
180